Soilproofing with quaternary ammonium derivatives of highly fluorinated carboxylic acids



United States Patent Ofifice 3,356,218 Patented Oct. 31, 1967 Thepresent invention relates to soilproofing textiles and to thesoilproofing quaternary ammonium compounds used and more particularly,to soilproofing textiles with quaternary ammonium compounds from highlyfiuorinated carboxylic acids and to the quaternary ammonium compoundsfrom highly fiuorinated carboxylic acids per se.

For centuries man has sought to alleviate the discomfort concomittantwith exposure to rain. One hundred years ago Maclntosh provided thecoated fabric which has, in subsequent years, provided a generic namefor a particular class of rainwear. It was not until about 1935 thatthere ,was any attempt to discover the factors controlling resistance towetting by water. Prior to this time, textile materials were coatedfabrics with various cookbook recipes such as rubber, linseed oil-rubbermixtures, empirical and whimsical synthetic dopes and other compositionshaving no basis in a discovery of the physical properties of apreparation which would impart to a textile the capability of waterrepellency. Without understanding the basic principles of surface freeenergy, contact angle, and spreading coefficient several unrelatedpractical developments arose during the half-decade from 1935 to 1940which changed the art of water-proofing textiles. In Germany, a seriesof paraffin wax emulsions were developed which, when padded ontotextiles, produced a high contact angle of water drops on the surfaceand a high degree of shower resistance without changing the porosity orair permeability of the textile material as do the preparationsrecommended for waterproofing prior to 1935. The treated fabrics werenon-wettable by water and water-borne liquids and stains because of thechange of the free energy of the fiber surfaces and not because theinterstices of the woven fabrics were plugged. Thus, a practicalimprovement was made without an understanding of the reason for theadvance in the art.

By the use of these new wax emulsion-metallic salts mixtures, it wasthen and is now possible to produce fabrics which have the feel andappearance of conventional fabrics but do not look like oil-cloths orfabrics having rubberized coating. The only practical limitation of suchmixtures is the durability to washing and drycleaning. This class ofwater-proofing materials generally comprise a mixture containing:

(a) A paraffin Wax or mixtures of vegetable wax esters such as carnauba,candelilla, or sugar cane wax.

(b) An emulsifying agent, usually glue, gelatin, and rosin soaps.

(c) An aluminum or zirconium salt, usually the formate or acetate. Theprimary function of the salt is to insolubilize the glue and otheremulsifiers after the emulsion is deposited on the fabric.

A large variety of such products are still in use as low-cost,non-durable water repellents for textiles. Since neither thermosettingnor fiber reaction occurs when textiles are coated with such products,the treated textile is non-durable to washing and dry cleaning. Otherthan water repellency for rainwater fabrics, such mixtures providefabrics with a fair degree of spot and stain resistance to Water-bornechromophoric materials.

The search for durable or permanent water repellents as contrasted withthese non-durable water repellents, especially for cellulosic fibers wasinitiated by the need to overcome the deficiencies of these waxemulsion-metallic salt mixtures. The first major advance occurred inEngland where a product marketed under the trade name Velan wasproduced. This material was octadecyloxymethyl pyridinium chloride, aquaternary ammonium compound made by the chloromethylation ofoctadecanol, followed by quaternization with pyridine to yield a producthaving a composition represented by the formula 015E310 ornN &

Where py is the balance of the pyridine ring. Fabrics treated with sucha compound are durably water repellent,

are porous, soft, and have the appearance of untreated fabrics.

A major improvement of the Velan type material was made when thestearamidomethyl analog of Velan commercially known as Zelan and NoraneR was produced. The advantage of the stearamide product is greaterinitial water repellency and greater durability to washing. Suchproducts are still among the forefront of the leaders in rainwear fabricfinishes.

In the search for other fabric-reactive or durable water repellentsother classes of compounds have been developed. Illustrative of theseother classes of water repellents are the silicone water repellentsmethyolsteararnide compositions (Permel, Ahcovel NW), hydrophobic resins(Norane GG, Ranedare R, Argus DWR), octadecylgetene dimer (Aquapel) andothers.

While durable water repellents had been initially developed forouterwear and raincoat applications, it was soon recognized that durableWater repellents could be used as finishes for other purposes. In theperiod 1950 to 1956 these durable water repellent finishes were Widelyused on mens suitings, dress goods, and upholstery materials. Whenolfering these products to the textile finishing trade, promotionalemphasis was not placed on Waterrepellency but on spot-andstainresistance. This use has continued to the present time. It had beenobserved that fabrics treated with such durable water repellents had ahigh degree of resistance to soiling by water-borne soils and stains andwere easier to launder. The primary limitation of these finishes wasthat they attracted rather than repelled oily soils, and the treatedfabrics were not resistant to staining by oily materials such as oils,greases, gravy, mayonnaise, etc.

In the early part of the 1950 decade based on work done at NavalResearch Laboratory by Fox and Zisman and from work done at a divisionof the Minnesota Mining and Manufacturing Co., the utility of certainfluorocarbon based chemicals as fibrous finishes was announced. Fox andZisman had demonstrated the physiochemical principle of low free energysurfaces and the relation of non-wetting with water or oils of surfacestreated with chemicals containing perfluoroalkyl groups.

The practical developments of 3M culminated in the introduction of thefirst product for textile treating. This product is still known asFC-149 and is a classical Werner complex of a carboxylic acid made byreacting one mol of the acid with two mols of basic chromic chloride.The compound is water soluble and cationic in nature. It exhibits strongadhesion to anionic substrates such as cellulose and fiberglass. It alsocomplexes with proteinaceous fibers such as wool, silk, and leather togive both water and oil repellent surfaces. It is generally believedthat perfluorodecanoic acid is the base for this product.

Subsequently, 3M made a product known as FC-208 available as a finish.It is generally believed that this finishing material is aperfiuorosulfonamide having a composition corresponding to the formulawhere x is an integer in the range of 3 to 13, R is methyl, ethyl,propyl, butyl, amyl, hexyl, R" is an alkylene radical having 1 to 12carbon atoms and R is hydrogen, methyl, or ethyl.

The advent of these perfluoro finishes produced a great practicalimprovement in fabric finishes. Although of little merit for plain waterrepellency for outerwear purposes, the two products, i.e., the WernerComplex and the perfiuorosulfonamide, offer a solution to the problem ofproviding fabrics with water-and-oil repellency and practical resistanceto staining. Because of its hydrolytic instability the Werner complexhas been limited to wool, leather, and upholstery finishes. Thesulfonarnide has become a leader in finishes for cotton, rayon, andnon-cellulosic synthetic fiber.

Important as water-and-oil repellency and resistance to staining bywater-and-oil borne stains are for wearing apparel, upholstery and thelike, the capability of shedding oily particulate soil is of greaterimportance. That is to say, the finely divided environmental grime mixedwith the oil exudations of the human skin, i.e., oily particulate soil,which soil the neckband and cuffs of a mans shirt are far more oftenencountered than soiling with gravy or mayonnaise. Hence, while fabricfinishes which repel water, oil, water-borne and oil-borne stains are ofgreat importance, the capability of resisting staining by oilyparticulate soil is of greater importance for aesthetic reasons if forno other reason. Yet even the perfluoro finishes presently available donot have the capability of resisting staining by oily particulate soil.In fact, they enhance such soiling.

It is manifest that controlled evaluating of fabric finishes in actualuse is not possible. Consequently, it has been necessary to useevaluation methods subject to laboratory control which will simulate asclosely as possible actual conditions under which water-repellency,oil-repellency, resistance to staining by water-borne and oil-bornestains, and resistance to staining by oily particulate soil of treatedfabrics occurs. Such methods of evaluation are the following.

Water Repellency (resistance to wetting (spray test) AATCC Standard TestMethod 22-1952) This test is applicable to any textile fabric. Itmeasures the resistance of fabrics to Wetting by a water spray and theresults depend primarily on the degree of hydrophobicity inherent in thefibers and yarns and subsequent treatments to which the fabric issubjected. Water is sprayed against the taut surface of a test specimen.Evaluation of the wetted pattern is readily brought about by comparingthe wetted pattern with standard wetting pattern pictures:

4 Characterized by: Rating No sticking or wetting of the upper surface100 Slight random sticking or wetting of the upper surface 9O Wetting ofthe upper surface at spray points Partial wetting of the whole of theupper surface 70 Complete wetting of the whole of the upper surface 50Complete wetting of the whole of the upper and the lower surfaces Thetest specimens of minimum size of 7" x 7" (seven inches by seven inches)are conditioned at 70 F. and 65 percent relative humidity for a minimumof four hours before testing. ii

The test specimen, fastened securely and wrinkle-fre in a metal hoophaving a diameter of 6 inches, is placed and centered 6 inches under astandard spray nozzle at an angle of 45 to the horizontal. Two hundredand fifty milliliters of water at 80 -2 F. is poured into a funnelattached above the spray nozzle. The spray lasts 25 to 30 seconds at theend of which time the hoop is taken by one edge and the opposite edgetapped smartly once against a solid object with the wet side facing thesolid; this procedure is repeated with the hoop reversed 180.

Oil Repellency (3M Textile Chemicals Appendix A- Test Methods, page 1)The Minnesota Mining oil repellency test is based on the differentpenetrating properties of the two hydrocarbon liquids, mineral oil(Nujol) and n-heptane. (NujoP is the trade name for white mineral orparaffin oil being a mixture of hydrocarbons having a density for lightoil in the range of 0.83 to 0.860 and for heavy oil in the range of0.875 to 0.905.) The Nujol-heptane proportions for each rating wereselected by 3M to give oily stain resistance somewhat comparable to thewaterborne strain resistance corresponding to each of the spray ratingsof the AATCC Standard Test Method 22-1952.

Oil Repelleney Percent Heptane Percent "NujoP Rating (by volume) (byvolume) N0 hold out to "NujoP.

The standard oil-heptane mixtures are contained in small stopperedmedicine-dropper bottles. A drop of each mixture of Nujol and heptane isplaced on the fabric. The appearance of the test oil is observed throughthe drop. Note is made whether wetting or penetration occurs. The numbercorresponding to that mixture containing the highest percentage ofheptane which does not penetrate or wet the fabric after three minutesis considered the oil repellency rating of the system.

The change in the optical refractivity of the drop is often anindication of wetting. In some cases wetting can be better determined byobserving the other side of the fabric. In some cases reportedhereinafter the term 0+ has been used to indicate a modicum ofresistance to wetting by oil.

Stain repellency The following procedures have been used to establishthe degree of resistance to starting by water-borne and oil-borne stainsof fabrics.

(a) The fabrics were stretched lightly on 12 x 31 frames. All or part ofthe frame was used depending upon the amount of fabric available. Theframes were supported at both ends with the fabric about 8 inches abovea black surface. The fabric touched nothing.

Appearance: Rating No stain visible 5 Slight stain 4 Easily noticeablestain 3 Y Considerable stain 2 Very heavily stained 1 Water stains 1)Instant tea 1 v (2) Sheaifers 232 blue-black Skrip (3) A & P Concordgrapejuice (4) Ann Page salad mustard (5) Boscd cholocate syrup v Oilstains Wesson Oil Gulf Supreme motor oil 20/20 (8) Oleomargarine 2 (9)La Rosa tomato sauce Jergens lotion 1 8 cc. dry powder/200 cc. waterapplied at 160 F. 3 Melted and applied at 160 F.

In reporting the relative resistance to staining and ease of stainremoval in laundering, the staining values for water-borne and oil-bornestains were averaged separately.

In all cases the stains were allowed to dry on the fabrics fortwenty-four hours before laundering.

Oily particulate soil repellency (GRC Dry Soil Test) Fifteen to twenty 6x 8" numbered specimens (normally 80 X 80 cotton), including at leastone untreated control, are tumbled for thirty minutes with 10 percent ofCyanamid Soil based on the weight of the fabric. The tumbling is carriedout in a 5-liter capacity Five Minute Home Cleaner at 44 r.p.m.; six No.8 neoprene rubber stoppers are distributed among the specimens toincrease the mechanical action. At the end of tumbling, the specimensare removed and each shaken separately up and down fifteen times by handto remove surface dirt.

The specimens are then cut in two (to produce two 4" x 6" pieces).One-half is washed with 50 grams of FAB in a cotton cycle with a S-pounddummy load, then hung to dry and lightly ironed under a clean cottoncloth.

The degree of soiling is determined with a photovolt reflectance meter(tri-blue filter). Six readings per specimen are made and the arithmeticaverage reported.

The Cyanamid Soil" described below is the same as that recommended byMinnesota Mining and Manufacturing Co. The following dry ingredients areblended thoroughly, dried in a forced draft convection oven for eighthours at 50 C., then milled for twenty-five hours with ceramic balls andstored in a polyethylene bag.

6 Cyanamid soil Material: Percent by weight Peat moss 38 Cement 17Kaolin clay 17 Silica, 200 mesh b 17 Furnace black 1.75 Red iron oxide0.50 Mineral oil 8.75

Peerless, R T. Vanderbilt.

Davidson Chemical Co.

Molacco. Benny & Smith Co.

C. K. Williams Co.

It has now been discovered that quaternary ammonium derivatives ofhighly fluorinated aliphatic carboxylic acids, i.e., aliphaticcarboxylic acids in which at least 70 percent to percent of the hydrogenatoms other than the hydrogen of the carboxyl group is replaced withfluorine and in which the terminal or omega carbon atom is attached totwo and preferably three fluorine atoms, have the capability ofimparting to or conferring upon textiles or textile substrates theresistance to wetting by water or oil, resistance to staining bywater-borne or oil-borne stains, and resistance to staining by oilyparticulate soil. In fact theaforesaid quaternary ammonium derivativesof highly fluorinated aliphatic carboxylic acids shed rather thanattract oily particulate soil.

The present quaternary ammonium derivatives of highly fluorinatedaliphatic carboxylic acids have compositions corresponding to thegeneric formula:

where Q is the alkyl moiety of an aliphatic carboxylic acid having threeto twenty-one carbon atoms and seven to forty-three hydrogen atoms ofwhich hydrogen atoms at least 70 percent up to 100 percent has beenreplaced with fluorine atoms and two and preferably three fluorine atomsare attached to the terminal or omega carbon atom of the fluoroalkylmoiety of the fluorinated aliphatic carboxylic acid, m is an integerhaving a value in the range of one to six and R, R", and R are the sameor different lower alkyl groups having one to six carbon atoms. Theaforesaid quaternary ammonium derivatives of aliphatic carboxylic acidshaving four to twenty-two carbon atoms in the molecule including thecarboxyl carbon usually are obtained as the salt of an anion such ashalide, sulfate, etc., corresponding to the formula:

where Q, R, R", R and m have the same significance as in (B) supra, andAn is an anion such as chlorine, bromine, iodine, ethosulfate, etc. Thequaternary ammonium derivatives of the present invention arecharacterized by having an amido as well as an aminonitrogen.

In general, the qu-aternary ammonium derivatives of the aliphaticoarboxylic acids are prepared by the reactions of classical organicchemistry. For example, the lower alkyl ester of highly fluorinatedaliphatic carboxylic acid is reacted with dialkyl aminoalkyl amine inequimolar proportions, the alcohol produced in the reaction removedpreferably at less than atmospheric pressure to obtain the intermediateamino-amide as a bottoms product, and the amino-amide reacted with analkyl halide, preferably the bromide, to obtain the quaternary ammoniumderivative of the highly fluorinated aliphatic carboxylic acid.

The mechanism of this particular method, of the several classicalmethods, of preparing these quaternary ammonium compounds is representedby the following equations:

Illustrative of the preparation of the quaternary ammonium derivativesof highly fiuorinated aliphatic carboxylic acids is the preparation ofhighly fiuorinated, i.e., pentadecafiuorooctyl amidopropyl dimethylethylammonium bromide. Thus, about 0.15 mol of the butyl ester ofpentadecafluorooctanoic acid and about 0.15 m-ol of dimethylaminopropylamine were reacted at a temperature in the range of 23 C. to40 C. for about seven hours. The butanol evolved was distilled at areduced pressure to obtain the intermediate amino-amide as a bottomsproduct in a yield of eighty-two percent of theoretical. Thirty parts byweight of the aforesaid aminoamide intermediate were reacted with 9.2parts by weight (about 0.085 mol) of ethyl bromide in thirty-five partsby weight of methanol for about four hours at a temperature in the rangeof 28 to about 80 C. A yield of 100 percent of theoretical of thepentadecafluorooctylamido propyldimethylethylammonium bromide wasobtained. The bromide of the quaternary ammonium derivative ofpentadecaoctanoic acid was soluble in water and ethanol.

The foregoing preparation ofpentadecafiuorooctylamidopropyldimethylethyl ammonium bromide isillustrated by the following equations:

or C F N H OBr (mol wt. 607).

Bromine: Calculated (?).Found (7).

The treatment of textile materials to obtain oil repellency andresistance to soiling by oily particulate soil may be typically carriedout by padding the textile to at least 80% wet pickup with thequaternary ammonium compounds of this invention and then curing the sotreated textile at a temperature of from room temperature to 350 F. andfor a period of time inversely proportioned to the temperature; the timeand temperature selected to be equivalent to about 5 minutes at 300 F.

The oil repellency and resistance to soiling by oily particulate soil ofthe QAC compound or pentadecafiuorooctylamidoisopropyldimethylethylammonium compound is indicated by the following data.

The higher the numerical value the less the adherence of the oilyparticulate soil.

When the textile is pretreated with 3 percent of a cationicurea-formaldehyde resin such as Uformite 467 available from Rohm andHaas Company and then treated with the aforedescribed QAC the resistanceto wet-ting by oil and the shedding of oily particulate soil is asindicated by the following data:

TABLE II Cured at Room Temp. Cured at 300 F. for

five minutes Percent Solids QACBr in water Reflectance Reflectance Oil011 B A B A 1 0+ 47 79 100+ 55 80 Untreated 0 31 79 0 31 79 It will beobserved that in both treatments the treated cloth (80 x 80 cotton) shedthe oily particulate soil before washing as indicated by the values of31 and 32 for the untreated cloth before washing and the values of 48,47, and 55 for the treated cloth before washing.

The quaternary ammonium compounds of the present invention, i.e., thehighly fiuorinated quaternary ammonium derivatives of the highlyfluorinated aliphatic carboxylic acids are recovered as the saltsthereof having compositions corresponding to the formula:

(C) O H R wherein Q is the alkyl moiety of an aliphatic carboxylic acidhaving three to twenty-one carbon atoms and seven to forty-threehydrogen atoms of which hydrogen atoms seventy to one hundred percenthas been replaced with fluorine atoms and two and preferably threefluorine atoms are attached to the terminal or omega carbon atom; in isan integer in the range of one to six inclusive; R, R, and R are thesame or different lower alkyl groups having one to six carbon atoms; andwhere in Formula C An is an anion e.g., chlorine, bromine, iodine,ethosu'lfate, and the like, are not to be confused with quaternaryammonium compounds described in the prior art. Thus, for example, in US.Patent No. 2,727,923 quaternary ammonium compounds conforming to theformula:

and R" are the same or different alkyl groups having one to five carbonatoms; and x is a halogen or hydroxyl clearly are not aminoalkylamidoderivatives of highly fluorinated aliphatic carboxylic acids.

Similarly, U.S. Patent No. 2,146,392 contains the description ofquaternary ammonium salts having compositions corresponding to theformula:

BOON H OH IIJ (tertiary) Where R is an aliphatic hydrocarbon radicalhaving two two seventeen carbon atoms; N (tertiary) is the nucleus of amolecule of pyridine, a c-alkylpyridine or quinoline; and X is amonovalent anion.

It is manifest that the quaternary ammonium compounds described in U.S.No. 2,146,392 are not aminoalkylamida derivatives of highly fluorinatedaliphatic carboxylic acids.

Quaternary ammonium salts of cellulose have also been described in theprior art. Thus, in U.S. Patent No. 2,768,162 there is the disclosure ofa quaternary ammonium salt of an aminoalkylether of celluloserepresented by the formula:

where R and R are hydrogen or aminoalkyl; R, R", R"" are alkyl oraralkyl; n is an integer of from two to four; and X is any anion.

Quite clearly the quaternary ammonium fraction of the aminoalkyletherdescribed in this patent is not aminoalkylamide derivative of analiphatic carboxylic acid nor of a highly fluorinated aliphaticcarboxylic acid.

In U.S. Patent No. 2,878,144 a fabric coated with quaternary ammoniumsalts of fatty acid esters of a polyhydroxypolyamine is described. Thiscoating material is not an amionalkylamido derivative of a highlyfluorinated aliphatic carboxylic acid.

Thus, the quaternary ammonium salts of the present invention are notdescribed in the prior art.

What is claimed is:

1. Aminoalkylamido derivatives of highly fluorinated aliphaticcarboxylic acids having compositions corresponding to the formula:

Q o-N (CH2) momN II I o H R" where Q is a hydrocarbon radical havingthree to twentyone carbon atoms and seven to forty-three hydrogen atomsof which hydrogen atoms at least 70 percent to 100 percent has beenreplaced with fluorine atoms and at least two fluorine atoms areattached to the terminal carbon atom; R and R" are alkyl groups havingone to six carbon atoms; In is an integer from 1 to 6.

2. Quaternary ammonium derivatives of compounds as defined in claim 1corresponding to the formula:

where R' is an alkyl group having 1 to 6 carbon atoms and An is ananion,

3. Pentadecafluorooctylamidopropyldimethylamine,

hydroxide, having the formula 5. A bromide salt of the quaternaryammonium hydroxide of claim 4.

6. Textile having aflixed thereto at least one quaternary ammonium saltas defined in claim 2.

7. Cotton haxing afiixed thereto at least one quaternary ammonium saltas defined in claim 2.

8. Textile associated with cationic resin and having a surfacecomprising at least one quaternary ammonium derivative as defined inclaim 2.

9. A method of imparting capability to shed oily particulate soil totextile material which comprises padding textile material to at least 80percent wet pick-up with at least one amidoalkyltrialkyl ammoniumderivative of highly fluorinated aliphatic carboxylic acid having fourto twenty-two carbon atoms in which at least percent to 100 percent ofthe alkyl hydrogens of said aliphatic carboxylic acid has been replacedby fluorine atoms and at least two fluorine atoms are attached to theterminal carbon atom, and curing the so-treated textile at a temperaturein the range of room to 350 F. for a period of time inverselyproportioned to the temperature and about five minutes at 300 F.

10. A method of imparting capability to shed oily particulate soil totextile material which comprises padding textile material with at leastone cationic resin, padding the so-treated textile to at least percentwet pick-up with at least one amidoalkyltrialkyl ammonium derivative ofhighly fluorinated aliphatic carboxylic acid having four to twenty-twocarbon atoms in which at least 70 percent to percent of the alkylhydrogens has been replaced by fluorine atoms and at least two fluorineatoms are attached to the terminal carbon atom, and curing theso-treated textile at a temperature in the range of room to 350 F. for aperiod of time inversely proportioned to the temperature and about fiveminutes at 300 F.

References Cited UNITED STATES PATENTS 2,727,423 12/1955 Husted260'567.6 2,743,297 4/1956 Husted et al 260561 2,878,144 3/1959 Conbereet al. 117-1395 X 2,878,273 3/1959 Conbere et al. 1l7l39.5 X 3,019,2611/1962 Pascal 260'-56.1 3,232,790 2/1966 Enders et al. 117-139.5

WILLIAM D. MARTIN, Primary Examiner. T. G. DAVIS, Assistant Examiner.

1. AMINOALKYLAMIDO DERIVATIVES OF HIGHLY FLUORINATED ALIPHATICCARBOXYLIC ACIDS HAVING COMPOSITIONS CORRESPONING TO THE FORMULA:
 10. AMETHOD OF IMPARTING CAPABILITY TO SHED OILY PARTICULATE SOIL TO TEXTILEMATERIAL WHICH COMPRISES PADDING TEXTILE MATERIAL WITH AT LEAST ONECATIONIC RESIN, PADDING THE SO-TREATED TEXTILE TO AT LEAST 80 PERCENTWET PICK-UP WITH AT LEAST ONE AMIDOALKYLTRIALKYL AMMONIUM DERIVATIVE ORHIGHLY FLUORINATED ALIPHATIC CARBOXYLIC ACID HAVING FOUR TO TWENTY-TWOCARBON ATOMS IN WHICH AT LEAST 70 PERCENT TO 100 PERCENT OF THE ALKYLHYDROENS HAS BEEN REPLACED BY FLUORINE ATOMS AND AT LEAST TWO FLUORINEATOMS ARE ATTACHED TO THE TERMINAL CARBON ATOM, AND CURING THESO-TREATED TEXTILE AT A TEMPERATURE IN THE RANGE OF ROOM TO 350*F. FOR APERIOD OF TIME INVERSELY PROPORTIONED TO THE TEMPERATURE AND ABOUT FIVEMINUTES AT 300*F.